JP2005069390A - Existing pipe replacing method and splitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To find a way out of limitation in the current construction by improving construction efficiency of an existing pipe replacing method by a current splitter construction. <P>SOLUTION: A connection propelling machine provided in a surface of the ground 1 obliquely inserts the rods 16 from the ground surface near a pile 14, while connecting the rods 16 to each other, and circularly pushes them for propelling, and inserts the rods 16 into the existing pipe 2 opened in the pile, and pushes them for propelling. When the rod 16 reaches a splitter 20, the splitter 20 is connected to the rod 16, and a replacing new pipe 12 is connected to the splitter 20. The replacing new pipe 12 is laid in the same route with the existing pipe 2, while vertically splitting the existing pipe 2 with a cutter blade 26a of the splitter 20, by pulling the rod. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a replacement method for an existing pipe that replaces an existing pipe laid on the ground with a new pipe, and in particular, a replacement method based on a splitter method that lays a new pipe in the same path while cutting the existing pipe with a splitter, It relates to a splitter used in the replacement method.

  As gas pipes and water pipes buried in the ground (hereinafter referred to as “existing pipes”), resin pipes such as vinyl chloride pipes are often used. However, for reasons such as aging, a new pipe is replaced with the same route as an existing pipe, and a splitter method is known as the replacement method.

  In this splitter method, as shown in FIG. 6, first, a vertical shaft is installed around both ends of a replacement portion 2 a of an existing pipe made of, for example, vinyl chloride (hereinafter referred to as “existing PVC pipe”) 2 laid on the ground 1. 3 and 4 are formed. Moreover, as shown in the figure, when the existing PVC pipe 2 has the supply pipe connecting portion 5, the shaft 6 is formed also in the vicinity thereof.

  Next, as shown in FIG. 7, the existing PVC pipe 2 exposed in the shafts 3 and 4 is cut, and the propulsion device 7 is installed in the shaft 3. The propulsion device 7 grips a steel rod 9 having a length of 60 cm, and propels the rod 9 toward the inside of the existing PVC pipe 2 by a hydraulic cylinder. During this propulsion, the rods 9 are manually added one by one. Reference numeral 8 denotes a packer that prevents gas leakage and prevents foreign substances from entering the pipe.

Then, as shown in FIG. 8, when the rod 9 at the tip reaches the shaft 4, the splitter 10 is connected to the rod 9. Four cutter blades 11 that are rotatably supported in a disk shape are attached to the splitter 10 at an angle of 90 ° with respect to the axis of the splitter 10. At the rear end of the splitter 10, a towing head 13 that holds the tip of a newly laid PE pipe (hereinafter referred to as “new PE pipe”) 12 is connected via a shackle (not shown). The Thereafter, the propulsion device 7 pulls back the rods 9 to collect them one by one, and the splitter 10 is propelled into the pipe of the existing PVC pipe 2. As a result, the cutter blade 11 cuts the existing PVC pipe 2 into four, and the new PE pipe 12 is laid on the same path inside. Such a conventional splitter method is described in Patent Document 1, for example.
JP-A-11-2362

  Since the conventional splitter method as described above does not require excavation of the ground over the entire length of the existing PVC pipe 2 in the replacement portion 2a, it can be said to be an excellent method particularly in terms of cost reduction. However, the length of one rod 9 to be used is as short as 60 cm, and the rod 9 cannot be safely connected or disconnected unless the rod 9 is stopped. In addition, these operations must be performed manually by a worker using a tool such as a wrench each time. For this reason, the work of connecting / disconnecting the rods 9 results in a significant time loss, and in an actual site where the construction time is restricted, the construction limit is 50 m per day at the longest.

  Further, in order to horizontally propel the rod 9 gripped by the propulsion device 7 in the pipe of the existing PVC pipe 2, it is necessary to finely adjust the installation posture of the propulsion device 7, and this work is also a factor of time loss. Yes.

  Furthermore, since it is necessary to install the propulsion device 7 in the shaft 3, it is necessary to secure a shaft 3 that is as large as possible, and it takes a long time to restore the shaft 3 after replacement.

  And if a large shaft 3 can be secured, the propulsion device 7 can use a higher output, but there is a limit to the size that can be secured in urban areas and roads where houses and buildings are densely packed, and after replacement It takes longer time to restore the shaft. For this reason, as for the performance of the propulsion device 7 that can be used at the actual site, the rod propulsion force is about 2 tons and the rod propulsion speed is about 1 m / min. It is a further factor of time loss.

  The background of the conventional splitter method is the present invention, the purpose of which is to improve the construction efficiency of the existing pipe replacement method by the conventional splitter method, and to break the existing construction limit. is there.

  In order to achieve the above-mentioned object, the present invention is a connected propulsion device that pushes and pushes against the ground while sequentially connecting a plurality of flexible rods, and pulls and pushes the rods while sequentially disconnecting the rods in the return direction. By this, the replacement method of the existing pipe which provides the new pipe for replacement on the same route as the existing pipe is provided.

  Specifically, a shaft is formed around both ends of the replacement part of the existing pipe laid on the ground, and the rods are connected by a step of cutting the existing pipe in each shaft and a connected propulsion unit installed on the surface of the ground. However, a step of pushing the rod in an oblique direction from the surface of the ground adjacent to one of the shafts, pushing it in an arc shape, inserting it into the pipe of the existing pipe that opens in the shaft, When the other shaft is reached, the splitter cutter is connected by connecting the splitter with the cutter blade to the rod and connecting the replacement pipe to the splitter, and by pushing the rod with the connecting propulsion machine. A method of replacing an existing pipe, including a step of laying a new replacement pipe in the same path as the existing pipe while vertically dividing the existing pipe with a blade.

  In this replacement method, the connection propulsion device drives the rod to the ground while sequentially connecting a plurality of rods during push-in propulsion, and pulls in the return direction while sequentially disconnecting the rods. For this reason, the connection work and connection release work of rods are automated, and construction efficiency can be improved. In addition, the connected propulsion unit is installed on the surface of the ground, not in the shaft formed around both ends of the replacement part of the existing pipe. For this reason, it is not necessary to finely adjust the installation posture of the connected propulsion unit in the shaft using a crane, etc., so it is possible to improve the construction efficiency, and no large shaft is required, and the existing pipe is cut. As a result, it is only necessary to form a small shaft as small as necessary for the connection work between the new pipe for replacement and the existing pipe, thus improving the construction efficiency of the shaft forming process and the shaft restoration process performed after laying the new replacement pipe it can. Furthermore, since the connected propulsion unit is installed on the ground surface, it does not depend on the size of the shaft that can secure its performance. Therefore, since a high output thing can be used, the rod propulsion force in pushing propulsion and pulling propulsion can be increased, the rod propulsion speed can be increased, and the construction efficiency can be improved.

  Regarding the replacement method, at least during push-in propulsion, a position information transmitter is built in the rod on the front end side in the propulsion direction, and the rod is freely propelled while guiding the propulsion direction based on the position information by the position information transmitter. Can be configured as More specifically, the rod can be freely propelled from the surface of the ground into the pipe of the existing pipe while guiding the propulsion direction based on the position information from the position information transmitter.

  In this replacement method, since the rod can be freely propelled, the approach from the surface of the ground to the pipe of the existing pipe can be accurately performed by the optimum route. More specifically, the rod can be propelled without damaging existing pipes that open in the shaft without being replaced. In addition, since position information can be obtained even within the existing pipe, the propelling position of the rod at the time of pushing propulsion and pulling propulsion can be easily grasped, and process management is easy.

  Regarding the splitter used in the replacement method, the front end connecting portion connected to the rod, the rear end connecting portion connected to the replacement new pipe, and the front end connecting portion and the rear end connecting portion around the axis of the splitter. And an intermediate portion rotatably attached to the intermediate portion, and a cutter blade is provided in the intermediate portion.

  According to this, even if the rod is rotated during the pull-in propulsion, the intermediate portion including the cutter blade is not rotated because it is rotatable with respect to the tip connecting portion. Further, the intermediate portion is also rotatable with respect to the rear end connecting portion. For this reason, even when a rotational force around the tube axis such as “swell” acts on the replacement new pipe when the replacement new pipe is retracted, the intermediate portion is rotatable. , Do not circulate with the rear end connecting part. As described above, since the circulation with the rod and the replacement new pipe is suppressed, the existing pipe can be cut linearly along the longitudinal direction, and the existing pipe can be cut in the circumferential direction by the cutter blade. There is no inconvenience such as breaking. Therefore, cutting efficiency increases and construction efficiency can be improved.

  In addition, the present invention provides a tip connecting portion that is connected to a rod that is pulled and propelled while rotating in the pipe of the existing pipe in order to improve the construction efficiency in the replacement method of the existing pipe, and drawing the existing pipe into the pipe For a splitter comprising an intermediate portion having a cutter blade that vertically cuts an existing pipe by propulsion, and a rear end connecting portion that connects a replacement new pipe to be laid inside the existing pipe that has been vertically cut, the intermediate portion is The splitter is characterized in that it is attached to the front end connecting part and the rear end connecting part so as to be rotatable around the axis of the intermediate part.

  According to this splitter, similar to the splitter in the above-described existing pipe replacement method of the present invention, the rotation of the rod connected to the front end connecting portion and the new replacement pipe connected to the rear end connecting portion is suppressed. Therefore, the existing pipe can be efficiently cut linearly along the longitudinal direction, and the construction efficiency in the replacement method for the existing pipe can be improved.

  For the splitter, the intermediate portion may be composed of a tapered portion that expands from the connecting side with the tip connecting portion, and a cutter blade holding portion that rotatably supports a disk-shaped cutter blade. it can.

  According to this splitter, for example, when the existing pipe enters the pipe end, contact with the existing pipe can be received at the tapered portion, and the contact load acting on the cutter blade can be reduced. The durability of the shaft support member can be improved.

  According to the existing pipe replacement method and the splitter of the present invention, since the construction efficiency can be improved as compared with the conventional one, the maximum construction limit can be greatly extended. As a result, the replacement of existing pipes is greatly promoted, and the safety and durability of lifelines such as gas pipes and water pipes as a whole can be increased, thereby contributing to society.

  Hereinafter, as an example of the best embodiment of the present invention, a method of replacing an existing PVC pipe as an “existing pipe” with a new PE pipe as a “replacement new pipe” will be described with reference to the drawings. In addition, about the same element as a prior art, the same code | symbol is attached | subjected and duplication description is abbreviate | omitted.

Vertical shaft forming step : As shown in FIG. 1, vertical shafts 14, 4, 6 are formed around both ends of the replacement portion 2 b of the existing PVC pipe 2 and around the supply pipe connecting portion 5. Here, since it is not necessary to install the propulsion device 7 in the shaft 14 on the start side, the length and width can be reduced as compared with the conventional shaft 3, and the restoration work is performed in a shorter time. It is possible. Moreover, as shown in FIG. 2, the existing PVC pipe 2 exposed to the shafts 14 and 4 is cut.

Pushing propulsion Step: Next, as shown in Figure 3, to form a small penetration hole 15 near the starting side of the vertical shaft 14, it will then push promoted by penetrating the rod 16 from here. The rod 16 used in this embodiment is made of hollow cylindrical steel, has a length of 3 m, and has flexibility that allows arcuate propulsion. Therefore, the length is five times that of the conventional rod 9, and the construction efficiency can be greatly improved. Each rod 16 has a threaded portion that is screwed and connected to the other rod 16 at both ends. An excavation rod 17 is connected to the foremost rod 16. The excavation rod 17 has an inclined surface 17a that receives earth pressure at its tip. A drilling fluid injection port (not shown) is formed at the tip. Drilling fluid is supplied to the injection port through a flow path (not shown) formed inside the rod 16 and the drilling rod 17, and the drilling fluid is sprayed in an oblique direction with respect to the axial direction of the drilling rod 17. To do. The excavation rod 17 incorporates a position information transmitter 17b. The position information transmitter 17b wirelessly transmits position information such as the depth from the ground surface and the propulsion angle of the excavation rod 17, and the current position of the excavation rod 17 is received by receiving this position information with a receiver on the ground. Can be understood.

  The rod 16 and the excavating rod 17 are propelled by a propulsion unit 18 as a “connected propulsion device” installed on the ground, and the propulsion unit 18 is driven by receiving power supply from a power unit 19 a mounted on a truck 19. The truck 19 can also be stopped at a place where there is no obstacle. The propulsion unit 18 has a storage portion 18a in which a plurality of rods 16 are mounted in advance, and a rod 16 that is automatically supplied from the storage portion 18a so as to apply pushing propulsion force, retraction propulsion force, and further rotational force. Part 18b. For this reason, the plurality of rods 16 provided in the storage unit 18a are automatically supplied to the propulsion unit 18b and are given rotational force and propulsion force along the screwing direction while being gripped by the propulsion unit 18b. Thus, it is possible to automatically screw and connect to the previously supplied rod 16. Therefore, compared with the conventional construction method which connects the rods 9 manually, construction efficiency can be improved significantly.

  The rod 16 and the excavating rod 17 are propelled by applying a rotational force and a propulsive force to the rod 16 gripped by the propulsion unit 18b, and confirming the position information from the position information transmitter 17b while checking the position information from the rod 16. By changing the jetting direction of the drilling fluid by rotating and stopping the rotation, it can be propelled freely in any direction and depth. Therefore, accurate free propulsion is possible in a pinpoint manner aiming at the opening of the existing PVC pipe 2 exposed to the shaft 14. In addition, since the rod 16 is flexible, it can be used for free propulsion in any direction and depth, and even when the existing PVC pipe 2 is laid in a curved shape, the existing PVC pipe 2 can be laid on the route. Follow-up is possible.

  The power unit 19a and the propulsion unit 18 in this embodiment that perform such free propulsion have a rod propulsion force of about 8 tons and a rod propulsion speed of 3 m / min. Therefore, compared with the conventional propulsion device 7, the rod propulsion force is about four times and the rod propulsion speed is three times, and the construction efficiency can be greatly improved. This is because the propulsion unit 18 is installed not on the shaft 14 but on the ground, so that the rod propulsion force is large and the rod propulsion speed is high without being restricted by the size of the shaft 14. is there.

  As described above, when the propulsion unit 18 pushes the rod 16 and the excavating rod 17 in an arc shape and reaches the starting shaft 14 as shown in FIG. 3, the push propulsion is continued as it is. Then, it is propelled into the pipe of the existing PVC pipe 2 opened to the shaft 14.

Connecting the splitter and the new PE pipe : As shown in FIG. 4, when reaching the shaft 4 on the arrival side, first the excavating rod 17 is removed, and then the splitter 20 is connected to the rod 16 in the same manner as in the conventional method. Further, the towing head 13 holding the new PE pipe 12 is connected to the splitter 20.

  As shown in an enlarged view in FIG. 5, the splitter 20 includes a front end connecting portion 21, an intermediate portion 22, and a rear end connecting portion 23. The distal end connecting portion 21 has a substantially cylindrical shape, and a threaded portion 21a that is screwed to the rod 16 is formed on the distal end side thereof. On the rear end side, an annular engagement portion 21b that protrudes outwardly is formed.

  The intermediate portion 22 includes a socket 24, a tapered portion 25, a cutter blade holding portion 26, and a connecting tail portion 27, which are separate parts.

  The socket 24 has a cylindrical shape, and an engagement step portion 24a with which the annular engagement portion 21b of the distal end coupling portion 21 abuts in the removal direction is formed on the distal end side of the inner peripheral surface, and on the rear end side. A screw portion 24b is formed.

  A threaded portion 25 a that is screwed with the threaded portion 24 b of the socket 24 is formed on the distal end side of the outer peripheral surface of the tapered portion 25. Therefore, the tip connecting portion 21 is rotated with respect to the socket 24 and the tapered portion 25 by inserting the tip connecting portion 21 into the socket 24 and screwing the screw portion 24b of the socket 24 with the screw portion 25a of the tapered portion 25. It is prevented from coming off while being held as possible. In other words, the annular coupling portion 21b of the distal end coupling portion 21 abuts the engagement step portion 24a of the socket 24 in the withdrawal direction in the withdrawal direction, so that the distal end coupling portion 21 is prevented from coming off. Further, the tapered portion 25 is formed with an elongated conical diameter-expanded portion 25b that gradually increases in diameter. Therefore, for example, when the existing PVC pipe 2 enters the pipe, the elongated conical diameter-expanded portion 25b comes into contact with the end of the pipe to buffer the impact, so that an excessive load is applied to the cutter blade 26a described later. This can be suppressed. And from the rear end of the taper part 25, the connection shaft 25c connected with the front-end | tip of the cutter blade holding | maintenance part 26 by screwing protrudes toward back.

  Four cutter blades 26a are attached to the cutter blade holding portion 26 with the angle shifted by 90 ° around the axis. Each cutter blade 26a has a disk shape, and an upper portion protrudes from the opening 26b. And since it is rotatably supported by the mounting screw 26c, the existing PVC pipe 2 is cut while rotating. Such a cutter blade holding portion 26 is connected to the connection tail portion 27 by screwing with a connection shaft 27 a protruding from the tip of the connection tail portion 27.

  The connecting tail portion 27 is formed in a columnar shape, and a protruding portion 27b having a multi-stage diameter reduction inserted into the rear end connecting portion 23 is formed at the rear end thereof. Reference numeral 27c denotes a threaded portion, into which a retaining nut 28 is screwed.

  The rear end connecting portion 23 has a cylindrical shape, and an engagement step portion 23a that engages with the retaining nut 28 in the removal direction is formed on the front end side of the inner peripheral surface thereof. Therefore, if the rear end connecting portion 23 is extrapolated with respect to the protruding portion 27b of the connecting tail portion 27 of the intermediate portion 22 and the retaining nut 28 is screwed into the screw portion 27c, the rear end connecting portion 23 becomes the connecting tail portion. 27 is held rotatably with respect to 27. Further, the rear end connecting portion 23 is formed with a pin hole 23c having a screw portion 23b. Therefore, when the shackle 13a of the towing head 13 is inserted into the rear end connecting portion 23 from the rear, the fixing pin 29 is inserted into the pin hole 23c, and is screwed into the screw portion 23b, the towing head 13 is moved to the rear end. It is connected to the connecting part 23. The new PE pipe 12 is connected to the splitter 20 by the connection of the towing head 13.

Retraction Propulsion Step : Next, as shown in FIG. As a result, the existing PVC pipe 2 is divided into four parts by the cutter blade 26a of the splitter 20, and the new PE pipe 12 is laid on the inside thereof.

  Also in this laying process, the propulsion unit 18b of the propulsion unit 18 can exert a large pulling propulsive force, so that the new PE pipe 12 is laid while cutting the existing PVC pipe 2 while substantially maintaining the rod propulsion speed described above. It is possible to improve the construction efficiency. The thickness of the cut in the supply pipe connecting portion 5 is increased, but the propulsion speed is not substantially delayed in this case, and it is possible to cut immediately and without difficulty, and the presence of the supply pipe connecting portion 5 Construction efficiency is not hindered.

  Further, at the time of pulling-in propulsion, rotation opposite to that at the time of pushing-in propulsion is applied to the rod 16. As a result, in the propulsion unit 18b of the propulsion unit 18, the connection between the rods 16 is automatically released and transferred to the storage unit 18a. Therefore, the connection efficiency between the rods 16 is hardly hindered. Absent. Then, although the rotation is applied to the rod 16 for the pulling propulsion, as described with reference to FIG. 5, the intermediate portion 22 with the cutter blade 26a is compared to the tip connecting portion 21 of the splitter 20 connected to the rod 16. It is free to rotate. Therefore, it is possible to efficiently cut the existing PVC pipe 2 linearly along the longitudinal direction by suppressing the rotation, and the existing PVC pipe 2 is divided in the circumferential direction by the rotation of the cutter blade 26a. Since it is possible to suppress inefficient cutting, construction efficiency can be improved. Moreover, the intermediate part 22 and the rear-end connection part 23 are connected so that rotation is mutually possible. Therefore, even when a rotational force around the tube axis such as “swell” is applied to the replacement new tube 12, the rear end connecting portion 23 only rotates, and the intermediate portion 22 is Since it does not rotate and rotates, efficient cutting is possible and construction efficiency can be improved.

  Finally, the new PE pipe 12 is connected to the existing PVC pipe 2, the supply pipe is newly connected, and the restoration work of the shafts 14, 4 and 6 is performed, whereby all the processes in the work area are completed.

  As described above, since the construction efficiency of the shaft 14 and the propulsion process of the rod 16, that is, the push-in propulsion process and the pull-in propulsion process, can be greatly improved, the construction time is the same as in the conventional construction method. The maximum construction extension of about 100 m (corresponding to the replacement part 2b in FIG. 1) can be easily secured, and the construction limit of the conventional method can be greatly overcome.

  Of course, the embodiment described above is only an example. For example, even if the existing PVC pipe 2 and the new PE pipe 12 exemplified as the gas pipe are pipe types of other materials and uses, the replacement method can be carried out. . Further, in order to increase the flexibility of the rod 16, the rod 16 may be made of a synthetic resin material, or only both end portions connected to other rods may be made of a metal material, and the intermediate portion may be made of a synthetic resin material. And although it was made to propel freely while guiding the excavation rod 17 from the penetration hole 15 to the vertical shaft 14, if it is not necessary, you may make it push-push without guide | inducing.

Process explanatory drawing of the replacement construction method of the existing pipe by one Embodiment. The schematic explanatory drawing of the process following FIG. The schematic explanatory drawing of the process following FIG. FIG. 4 is a schematic explanatory diagram of a process following FIG. 3. The expanded explanatory view containing the partial cross section of a splitter. Schematic explanatory drawing of the process following FIG. Process explanatory drawing of the replacement construction method of the existing pipe by one conventional example. Schematic explanatory drawing of the process following FIG. Schematic explanatory drawing of the process following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground 2 Existing pipe 3, 4, 6 Vertical shaft 7 Propulsion device 9 Rod 10 Splitter 11 Cutter blade 12 New pipe 14 Vertical shaft 15 Penetration hole 16 Rod 17 Excavation rod 17a Inclined surface 17b Position information transmitter 18 Propulsion unit (connection propulsion unit)
20 Splitter 21 Front end connecting portion 22 Intermediate portion 23 Rear end connecting portion 25 Taper portion 25b Diameter increasing portion 26 Cutter blade holding portion 26a Cutter blade 27 Connection tail portion

Claims (5)

Replaces the same path as the existing pipe by a connected propulsion machine that pushes and pushes against the ground while sequentially connecting multiple flexible rods, and pulls and pushes the rods in the return direction while sequentially releasing the connections between the rods. A replacement method for existing pipes that lay new pipes
Forming a shaft around both ends of the replacement part of the existing pipe laid on the ground, and cutting the existing pipe in each shaft;
An existing pipe that opens in the shaft by connecting the rods with a connecting propulsion machine installed on the surface of the ground and penetrating the rod diagonally from the surface of the ground close to one shaft and pushing it in an arc. A process of inserting into the pipe and pushing in as it is,
If the rod reaches the other shaft, connecting a splitter with a cutter blade to the rod and connecting a replacement pipe to the splitter;
Replacing the existing pipe, including the step of laying the new pipe for replacement in the same path as the existing pipe while vertically dividing the existing pipe with the cutter blade of the splitter by performing the pull-in promotion of the rod by the connected propulsion machine Construction method.   The rod according to claim 1, wherein at least during push-in propulsion, a position information transmitter is built in the rod on the front end side in the propulsion direction, and the rod is freely propelled while guiding the propulsion direction based on the position information by the position information transmitter. Replacement method for existing pipes.   The splitter includes a front end portion connected to the rod, a rear end portion connected to the replacement new pipe, and an intermediate portion attached to the front end portion and the rear end portion so as to be rotatable around the splitter axis. The replacement method for an existing pipe according to claim 1 or 2, wherein a cutter blade is provided at the intermediate portion. A tip connecting portion that is connected to a rod that is pulled and propelled while rotating in the pipe of the existing pipe, an intermediate portion that includes a cutter blade that vertically cuts the existing pipe by pushing the existing pipe into the pipe, and a vertical cut In a splitter comprising a rear end connecting portion for connecting a replacement new pipe to be laid inside the existing pipe,
A splitter characterized in that the intermediate part is attached to the front end connecting part and the rear end connecting part so as to be rotatable around the axis of the intermediate part.   5. The splitter according to claim 4, wherein the intermediate portion includes a tapered portion whose diameter is increased from a connecting side with the tip connecting portion and a cutter blade holding portion that rotatably supports a disk-shaped cutter blade.

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